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<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      class Person {
        constructor() {
          // this = {};
          // this.__proto__=Person.prototype
          // return this;
        }
        say() {}
        add() {}
      }
      // Person.prototype.say = function () {};
      // Person.prototype.add = function () {};
      const p1 = new Person();
    </script>
  </body>
</html>
